Dash-pot.



O. H. HAPGOOD.

DASH POT. APPLIGATION FILED MAR. 28. 1912.

1,119,013. Patented Dec. 1,1914.

"UNITED STATES P TENT @FFICE.

CLARENCE H. HAIPGOOD, 0F II-015E110, OHIO, ASSIGNOR TO TOLE DO SCALECOMPANY, OF TOLEDO, .OHIO, A CORPORATION OF NEW JERSEY.

DASH-POT.

Specification of Letters Patent.

Patented Dec. 1, 1914..

Application filed March 28, 1912. Serial No. 686,979.

To all whom it may concern 1 Be it known that I, -CLARENCE H. HAP- eooo,'a citizen of the United States, residing at Toledo, in the countyofLucas and State of Ohio, have invented certain new and useful IImprovements in Dash-Pots, of which the following is a specifieation.

My invention is particularly adapted to dashpots for use in scales tocontrol the vibration and sudden movement thereof for the reason that itautomatically adjusts itself to different temperatures, exerting thesame effect upon the movement of the beam whether it be hot or cold. Indashpots for this purpose it is the usual practice to employ oil as theliquid because of its lubricating and non-volatilizing properties, butit has been found to have a serious defect in that its fluidity changeswith variations in temperature, the oil becoming more viscous as the.temperaturelowers and thus exerting a greater retarding action upon thescale beam. It has been found necessary, therefore, to provide somemeans for regulating the flow of the oil and this has been doneheretofore by a hand-controlled regulation of the'openings through thepiston for the flow of oil. It is,'however,' a matter of some difficultyto properly adjust the regulation and furthermore it requires frequentattention where the temperatures vary from time totime.

My invention consists in automatic means for controlling the. openingthrough the piston and a preferred embodiment thereof is disclosed inthe accompanying drawings and described in [the following specification.But it is to be understood that the form specifi cally shown anddescribed, while pre erred by me, is but an exemplificat'ibn of theinvention andmany changes and departures therefrom may be madewithin thescope of my invention as set forth in the following.

claims.

Referring to the drawings accompan ng and forming part of thespecification, ig-

ure 1 is a side elevation, partly in section, of the preferred form ofdashpot; Fig. 2..

known or approved form, and as shown is perforated at 7 to receive a rod8, secured therein by a screw 9, the outer end of the rod beingdownwardly turned as at 10, and perforated to receive a pin 11, to whichthe upper end of the piston rod 12 is pivoted. The piston 13 isvertically movable in the dashpot l4, and the latter in the particularstructure shown is provided with an attaching flange 15 and a cover 16,the latter of whichjmay be secured to the dashpot by a screw v thread orother suitable connection. From the center of the dashpot cover rises aperforated boss or sleeve 17, through the perforation of which extendsthe piston rod 12, and the latter carries at its upper end an invertedthimble 01 barrel 18 surrounding the sleeve 17 the two telescopingmembers coiiperating to prevent the splashingof Oll he various parts-sofar described form no part of the present invention which is concernedmore particularly with the piston head and parts carried thereby. Thepiston head consists of a perforated disk 13 to which the piston rod 12is attached in any suitable. manner as by swaging, and is The lowercollar 24 is spaced from the pi's ton head 13 a sufficient distance toprovide for the passage of the shutter 20 thereunder and the latter isnotched or recessed at the side as at 26 to permit, it to swing withoutinterference from the piston rod. A thermostat 27 composed as is commonin instrumentalities of this nature of two strips of metal of unequalindices of expansion, is i connected at one end to the short end 28 ofthe shutter, that is to say, the end beyond its pivot, and at its otherend the thermostat is anchored to an car 29 upon the plate 23.Intermediate its ends the thermostat takes the form of a divided ringlying just within the periphery of the piston and upon the upper face ofthe latter.

It will now'be readily understood that if the outer member of thethermostat have a greater index expansion than the inner member, anincrease in temperature will course upon the rise in temperature. Thusastheoil becomes more sluggish, due to a change in temperature, theopening through the piston is substantially enlarged, and with increasedfluidity due to a rise in temperature the opening of the piston iscontracted. The control is entirely automatic and the device needs nomanipulation after it has once been installed. I have found in practicethat brass and steel may be advantageously employed as the metals forforming my thermostat though other metals may be employed, and in actualuse the former as that having the larger indices of expansion hasconstituted the outer member. It will be obvious, however, that bysuitable rearrangement and adjustment of the parts the moreexpansiblemember may be arranged on the inside in which event the thermostat willmove the shutter by expansion to contract the opening. While the dashpothas been described in connection with a scale mechanism it is obviousthat its use is not limited thereto but that it is applicable to anyother situation in which it is desired that .the action of the. deviceshall not change with changes of temperature.

I claim:

1. A dashpot comprising a cylinder and piston, the latter formed with anopening for the passage of oil, a pivoted shutter the long arm of whichcontrols the opening and a thermostat connected to the short arm of theshutter.

A dashpot comprising a cylinder and piston the latter formed with anopening for the passage of oil, a shutter for the opening pivoted at apoint remote from the latter and a thermostat one end of which is fixedwith relation to the piston and the other end attachedto the shutter ofthe body of the thermostat intermediate its ends being formed into thearc of acircle and lying upon the face of the piston.

3. A dashpot comprising a cylinder and a piston, a shutter pivoted tothe piston, an opening controlled by said shutter upon the opposite sideof the center of the piston from the pivotal point and a partiallycircular thermostatic element arranged concentric to the piston andanchored thereto at one end and attachedto the shutter at the other tooperate the latter.

4:. In a dashpot, a cylinder, a piston therein having an openingtherethrough, a plate 23 attached to the rod of the piston, a shutter20. pivoted to said plate and arranged to cover and uncover the openingthrough the piston and a partially circular thermostatic element.anchored to said plate at one end and connected to the shutter at theother.

CLARENCE H. HAPGOOD.

Witnesses:

E. E. LENGENECKER,

J. D. BURKHOLDER.

